Comparison on Identification of Affective Body Motions by Robots Between Elder People and University Students: A Case Study in Japan

Expressive behaviors based on body motions are one of the useful methods that social robots present their emotional states toward users. On the other hand, some psychological research found age dependence on emotion identification in human facial expressions. In order to investigate this dependence in affective body expressions of robots, a psychological experiment was conducted in Japan, by using a small-sized humanoid robot on which three types of affective motion expression (anger, sadness, and pleasure) were implemented. The results of the experiment, which consisted of seventeen university student subjects and fifteen elder subjects, showed differences between younger and elder subjects on emotion identification, body parts paid attention to, and impressions of motion speed and magnitude for these affective body motions of the robot. Moreover, the results suggested correlations between the accuracy of emotion identification and cognitive bias to the robot's specific body motion parts. Based on these results, the paper discusses about some implications in human-robot interaction research.